Paper on PaLM is a large GPU cluster operated by Google, located in the United States, in the private sector. It came online around April 2022. At that moment it ranked number 15 among known clusters.
It is built on 6,144 Google TPU v4. That amounts to about 854 H100e of AI compute. The cluster draws roughly 4.45 MW. Its hardware is estimated at $56M.
Epoch AI rates the certainty of this record as confirmed.